In recent years, with development of the mobile communication technology, ability of the mobile communication system for supporting wireless communication business has been significantly increased. However, users raise higher requirements for multimedia service with high rate and quality. Therefore, in research of next generation of the mobile communication technology, higher requirements are raised in respect of aspects, such as spectrum efficiency, transmission rate, system throughput, and cell-edge performance and the like. Orthogonal Frequency Division Multiplexing Access (OFDMA), as one of key technologies for next generation of the wireless communication system, can reduce intra-cell interference effectively, but it cannot get rid of affection of inter-cell interference, which results in degradation of system performance. Specifically, for the cell-edge user with lower Signal to Noise Ratio, incorrect encoding caused by strong interference might lead to greatly reducing of throughput. Since coordinated Multi-point Transmission/Reception (COMP) technology can improve performance of cell-edge users, and reduce or even eradicate the inter-cell interference, it has been widely focused on and researched by industry in recent years and becomes an important study project of 3GPP LTE-Advanced standardization.
The concept of CoMP communication technology is expanding a conventional cellular network to be a Multiple Input Multiple Output (MIMO) system of multiple cells, i.e., multiple cooperating base stations provide service for cooperating users by simultaneously using same wireless resources. Thus, signal from a neighbor cell is used as auxiliary transmission signal, instead of dominant interference resources, to provide service for the cooperating users. However, great challenge is brought for user schedule and wireless resource allocation when introducing the new technology of CoMP communication technology. Schedule and resource to allocation is performed among multiple cooperating cells, which means that the scale of a complicated problem is further enlarged and the constraints for the problem is increased and stricter.
At present, enormous efforts have been made for solving the problem of schedule and resource allocation of CoMP system. For example, D. Choi, et al., proposed a solution for schedule and resource allocation of CoMP system with multiple carriers (D. Choi, D. Lee, J. Lee, Resource allocation for CoMP with multiuser MIMO-OFDMA, IEEE Trans. On Vehicular Technology, vol. 60, pp. 4626-4632, November 2011). Three modulating modes, which are supported by LTE system, are used in the solution of the prior art and the influence of frequency-selective channel is considered as well, which means that the solution can be used directly in next generation of communication system based on OFDM. However, in order to reduce complexity, joint optimization problem in the prior art is solved through proceeding two independent steps, i.e. determining schedule plan at first, and then performing bit and power allocation based on the plan. In addition, an allocation way based on a greedy algorithm is adopted, wherein, on the condition of satisfying power constraints of each base station, one bit is allocated each time to a user which needs the minimum transmission power for transmitting an extra bit and its corresponding subcarrier. Since the solution in the prior art separates the schedule and the resource allocation apart and the greedy algorithm only can select the presently best result, the application of a suboptimum algorithm, which can not consider the overall interests, in the solution of the prior art will inevitably affect the schedule of the whole system and the resource allocation capability.